This document provides an overview of World War 1, including: - The war lasted from 1914-1918 and was caused by opposing alliances between the Allies (Russia, France, UK) and Central Powers (Germany, Austria-Hungary, Italy). - Germany unified in 1871 but entered colonial expansion late. - International crises in the early 20th century increased tensions until the assassination of Archduke Franz Ferdinand led Austria-Hungary to declare war on Serbia, drawing in the other powers. - The war was initially expected to be short but stalemated into trench warfare on the Western, Eastern, and Balkan fronts by the end of 1914.